Method for treating wood



y 1937. F. w. CHERRINGTON 2,087,965

METHOD FOR TREATING WOOD Filed Jan. 29, 1955 Patented July 27, 1937umice mm FATEN'E" 4 Claims.

This invention relates to a method for treatingwood, and is moreparticularly directed to the treatment ,of timbers, logs, ties, orsimilar large bodies of wood with a preservative such 51 as creosoteoil, paraffin, or the: like, or with a fireproofing solution,containing, for example, sodium acetate.

Ithas'heretoiore been considered that a preservative treatment could beefiectively administeredto wood only after the wood had been thoroug hlydried to remove as -much of the moisturecontent as possible. For thisreason, it has been the practice to store large quantities of the greenlumber to await natural drying and then .to treat-the lumber by forcingthe preserving liquid'into the grain by hydraulic pressure. The successof, this method has bee n variable, .since the'penetrationof thepreservative varies with the kind of wood under treatment, and thedegree of .drying previously imparted thereto. .If is, method cannot besuccessfully employed -with green wood as it is practically impossibleto force preserving liquid intoa green body of wood to: a;-d ep-th whichwould satisfy even the most len; nt commercial requirements.

has now been-found that it is possible to obtain a complete penetration,of the preservative while flthewood is in its green, wet condition, andthat this may be accomplished in a very short time providing thepenetrating force is exerted lengthwise of the log, as by centrifugal iaction.

The primary object of the present invention is the provision of a novelmethod for introducing preserving liquid into green wood.

Another object of the invention is the provision of such a method whichincludes the introduction of preserving liquid lengthwise oi the log orwood body, while the wood is in its green or undried state.

Another object of the invention is the provision of a simple andef'ncient apparatus to carry out my method of treating wood.

Other objectsand advantages of the invention will become apparent as thedescription proceeds, reference being had to the accompanying drawing,in which an apparatus is disclosed which illustrates the principles ofthe invention, and in which- Figure 1 is a fragmentary side view of anapparatus suitable for my method; Fig. 2 is a plan View with parts insection, taken on line 2-2 in Fig. 1; Fig. 3 is a perspective detailedview of a retaining key; Fig. 4 is a perspective view of a suitablereceptacle for the wood to be (Cl. in -2i) treated; Fig. 5 is afragmentary section on. line 55 in Fig. 4; Fig. 6 is a detailed View ofa suitable closure for the wood receptacle, and Fig. 7 is a fragmentarysection at in Fig. 4.

Referring to the drawing, one form of the apparatus which may be mod tocarry out my method, particularly as applied to railway ties, includes arotatable table member l mounted on a central standard 2 andbraced initsrotary movements by wheels i adapted to run on a circular track 5..The track may be carried by any suitable means such as a concrete bed.6. The entire machine is preferably disposed in a pit, or otherwisesuitably protected around its periphery.

A gear I is carried by the rotatable table member l and is in mesh witha pinion 8 driven by a suitable motor 9, which is mounted on the stationary central standard 72, and is thus adapted to rotate the table [1.20

As will be seen in Figs. 4 and 7, I prefer to encase each tie A, orpiece or wood, to be treated in a suitable. receptacle such as arectangular metallic member it having its inner end open while the woodis being placed therein, and its outer end inturned to form sharp edgesit? which engage the wood, and in use form a seal therewith. The outerend is entirely open except for the space required to form the inturnededges for a purpose which will presently become apparent. Thus, the woodis entirely encased except at the outer end. At its inner end. eachreceptacle is provided with means to attach to a centrally disposed hubl8, which means may include slots M each adapted for the reception ofone side of an H-shaped retaining key l5 shown in Fig. 3. The other,similar half. of the retaining key is adapted to be fitted into a slot55 formed in the hub it carried by the rotary table. The hub It may haveany number of sides, each of which is adapted to carry one of the tiereceptacles. The hub is provided with a central preservative dispensingconduit 29 from which branch pipes '22 project, one for each of thereceptacles. A flexible coupling it extends from each branch conduitand, in use, connects to a stub pipe 26 carried adjacent the inner endof each receptacle and behind the innermost portion of the tie to betreated. Suitable valves 23 control the flow of preserving liquid ineach branch while a main valve Sill controls the flow in the dispensingconduit 2b.

In treating ties according to my method, each tie is placed in areceptacle i8, and a backing plate 32 slid into the receptacle after thetie to close oif the inner end. Thus, the ties are each entirelysurrounded except for one end. The receptacles are then placed on thetable I with their inner ends adjacent the hub 58. The H-shapedretaining keys are then forced into place, and the couplings 2d arefixed to the stub pipes carried by each receptacle, and the controlvalves 28 are opened. It will thus be seen that the entrance for thepreserving liquid is disposed between the innermost end of the tie andthe backing plate 32, and at the same time entirely surrounds the tieexcept for the central part of the outer end of each tie. The machine isthen set in motion and the preserving liquid is allowed to enter eachcase. Since the ties are radially disposed with relation to the axis ofrotation, the centrifugal force set up by the machine will force thecreosote, or other preserving liquid, longitudinally through the ties inthe di rection of the sap ducts, which are naturally present in thewood. .The creosote is thrown off from the outer end of the tie anddrops into the pit and may be re-used, and, by being retained, it mayeasily be estimated as to the quantity of preservative retained by eachcubic foot of wood treated.

It has been found that when the speed of a machine fourteen feet indiameter is approxi- I mately 40 to 90 R. P. IVL, a liquid as heavy ascreosote oil will entirely impregnate green or undried oak tiesimpartially through both heart and sap wood and flow from their outerends in a space of about two minutes. It will be appreciated thatrepresents an enormous saving in time over the old methods, whichrequired that the oak ties be dried approximately one year before beingtreated. It will be seen that the preserving liquid is forced by thecentrifugal action set up by the rotation of the machine lengthwisethrough the sap ducts of the tie and allowed to flow freely from theouter end since the casing ill is open at this point.

While I have disclosed one machine which is suitable for carrying out mymethod, it should be expressly understood that this disclosure is madepurely by way of illustration, and that the method is capable ofpractice with various other machines and that numerous changes may bemade in the form and disposition of the parts without departing from thespirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire tosecure by United States Letters Patent, is:

1. The method of treating wood. With a preserving liquid which consistsin rotating green or undried wood about an axis with its grain or ductsradial of the axis and introducing the preserving liquid at the pointnearest the axis of rotation, whereby centrifugal force causes thepreserving liquid to flow longitudinally of the grain or ducts.

2. The method of treating wood with a preserving liquid which consistsin placing a piece of green or undried wood to be treated in a casinghaving one end substantially open, rtating the wood and casing about anaxis with the grain of the wood radial of the axis and introducing thepreserving liquid into the casing at a point near the axis of rotationwhereby centrifugal force causes the liquid to flow through the woodlongitudinally of the grain, and out of the open end of the casing.

3. The method of treating wood with a preserving liquid which consistsin rotating green or undried woodabout an axis with its grain or ductsradial of the axis and introducing the preserving liquid at the pointnearest the axis of rotation, sealing the outer part of the outer end ofthe wood by centrifugal force whereby the same centrifugal force causesthe preserving liquid to flow longitudinally of the grains or ducts.

4. The method of treating wood with a preserving liquid which consistsin placing a piece of green or undried wood to be treated in a casinghaving one end substantially open, rotating the wood and. casing aboutan axis with the grain of the wood radial of the axis and introducingthe preserving liquid into the casing at a point near the axis ofrotation whereby centrifugal force causes the wood to be sealed at itsouter end against the casing and the liquid to flow through the woodlongitudinally of thegrain, and out of the open end of the cas- FRANK W.CHERRINGTON.

